Communication switching system, with marker, register, and other subsystems coordinated by a stored program central processor

ABSTRACT

A stored program computer is used for functions such as digit analysis and routing control where flexibility is important, while a wired logic time division multiplex register-sender subsystem is used to receive dialing and other call signals and to control outpulsing which require relatively fixed functions of a repetitive nature. A reed relay switching network is controlled by wired logic markers which perform path selection functions as well as supplying operating potentials for the network relays. The originating marker also performs the function of scanning the lines for originating calls, identifying the calling line and selecting a path through the network to a register junctor. Direct data communication is provided between the originating marker and the data processor computer for sending an originating message identifying the calling line and the register junctor. There is also a direct communication path from the computer to the terminating markers to send them messages identifying terminals to be connected to complete a call. The data processor includes a separate drum memory system with its own processing logic circuits for performing functions such as translations and providing an extended memory for some programs for the computer. The data processor computer communicates with the register-sender subsystem by direct access to the register-sender memory on a random basis, arranged so as not to interfere with the cyclical access by the register-sender subsystem.



1. A communication switching system comprising: a switching network having a plurality of terminals, a plurality of line circuits individually connecting communication lines to individual ones of said terminals, a plurality of register junctors individually connected to other of said terminals; originating marker means and terminating marker means for controlling the switching network, each of the marker means including apparatus to select a path and establish a connection between two selected terminals, the originating marker means further including means to detect originating call requests via the line circuits and to select and identify one calling line circuit at a time for service, to select an idle junctor for the call, and to select and establish an originating connection between the originating line circuit and the selected register junctor; a register subsystem including a register memory which has junctor memory areas permanently assigned to the register junctors, and common logic means, time division multiplex means with sequential cyclically recurring time slots for the register junctors to access the junctor memory areas and the associated register junctors to process information from the memory and the register junctor and to store data into the junctor memory area; a data processing unit which includes a central processor and a central processor memory, data communication means interconnecting the central processor with the originating marker means and the terminating marker means, the originating marker means including means effective after said originating connection between a calling line circuit and a register junctor has been selected to seize the data communication means and transmit an originating data message identifying the calling line circuit and register junctor terminals to the central processor, means in the central processor responsive to receipt of said originating data message to assign a portion of the central processor memory to the call as a call history table; means in the data processing unit to find class of service information relating to the calling line to be used in processing the call, data transfer means interconnecting the central processor and the register subsystem, means effective after the central processor has assigned said call history table to a call to transmit information via the data transfer means to a register subsystem for storage in the junctor memory area for the register junctor which has been selected for the call; the register subsystem being effective to receive and store dialed digits for the call, and to transmit information relating to the dialed digits via said data transfer means to the central processor for processing, the central processor including means to process the call and transmit a terminating data message via said data communication means to the terminating marker means, the terminating marker means being responsive to the receipt of the terminating data message to select a path and establish a connection in the switching network between the calling line circuit and a selected terminating terminal; and means responsive to both the register subsystem and the central processor as well as the terminating marker means completing their functions for a call to return both the junctor memory area and the call history table to an idle state.
 2. A communication switching system as claimed in claim 1, wherein said central processor comprises a stored program computer operating with said central processor memory.
 3. A communication switching system as claimed in claim 2, wherein said data processing unit includes an auxiliary processor having its own memory including apparatus for associative searches, arranged to operate with said central processor to receive data therefrom, to use the associative search apparatus to find correspondence between a part of the data and information in the memory of the auxiliary processor, to extract related information from the memory of the auxiliary processor and return it to the central processor, while the central processor is independently proceeding with the execution of other routines.
 4. A communication switching system as claimed in claim 3, wherein the memory of the auxiliary processor is used as an extended memory for storing programs which upon request from the central processor are transferred to the central processor memory for execution, the transfer being effected without interference with the simultaneous processing of other routines by the central processor.
 5. A communication switching system as claimed in claim 4, wherein said auxiliary processor is a drum memory system in which its memory comprises magnetic drum means.
 6. A communication switching system as claimed in claim 2, wherein said data transfer means interconnecting the central processor and the register subsystem comprises means for a direct access from the central processor to the register memory on a random access basis, with means to prevent interference with the sequential access by the register subsystem to the junctor areas in the respective time slots.
 7. A communication switching system as claimed in claim 6, wherein said common logic means of the register subsystem includes wired logic with sequence control means.
 8. A communication switching system as claimed in claim 1, wherein said originating marker means and terminating marker means each include wired logic apparatus with sequence control means, and wherein said data communication means interconnecting the central processor with the originating marker means and the terminating marker means comprises serial data transmission apparatus.
 9. A communication switching system as claimed in claim 8, wherein said register subsystem includes sending means for outpulsing on calls to other offices; wherein for all the dial pulse mode of direct current signaling, there is an arrangement comprising multiplex means to effectively connect the common logic means and the register junctors during their respective time slots for receiving and sending from or to relay repeating means in the register junctors; wherein for tone signaling comprising a combination of tones for each digit, there are provided receivers and senders and a switching matrix for selectively connecting them to the register junctors, each receiver or sender being accessed on a time-division multiplex basis from the common logic during the time slot associated with the register junctor to which it is connected.
 10. A communication switching system as claimed in claim 9, wherein said central processor and said register subsystem are each provided in duplicate and operated in synchronism to process the same call information, With each central processor normally communicating with a given one of the register subsystems, one of the central processor-register subsystem combinations being on line to supply output information ot other subsystems, and wherein the system may be reconfigured with either central processor communicating with either register subsystem, and any combination of them being on line to supply output information.
 11. A communication switching system as claimed in claim 10, wherein said originating marker means is duplicated with both operating simultaneously, interlocked so that any given call request is served by only one originating marker; and wherein said terminating marker means is duplicated and arranged to operate only one at a time, with reconfiguration means permitting either originating marker means or either terminating marker means to be temporarily taken out of service.
 12. A communication switching system as claimed in claim 11, wherein said data processing unit includes an auxiliary system with its own memory, the auxiliary system being duplicated, with both or either central processor working with either auxiliary system.
 13. A communication switching system as claimed in claim 12, wherein the system includes a control section comprising one said data processing unit and either one or two said register subsystems depending upon the call processing traffic load of the system, and wherein in a control section comprising two register subsystems said data transfer means comprises an arrangement for the central processor to selectively communicate with the register memories of both register subsystems. 